C# 如何处理多个相同的异常？

Question

在我的代码中，我有一个包含多个 catch 语句的方法，这些语句执行所有相同的语句。我不确定这是实现它的正确方法。你会怎么做？

public void LoadControl(ControlDestination controlDestination, string filename, object parameter)
{
    try
    {
        // Get filename with extension
        string file = GetControlFileName(filename);

        // Check file exists
        if (!File.Exists(file))
            throw new FileNotFoundException();

        // Load control from file
        Control control = LoadControl(filename);

        // Check control extends BaseForm
        if (control is BaseForm)
        {
            // Set current application on user control
            ((BaseForm)control).CurrentApplication = this;
            ((BaseForm)control).Parameter = parameter;

            // Set web user control id
            control.ID = filename;

            Panel currentPanel = null;

            switch (controlDestination)
            {
                case ControlDestination.Base:
                    // Set current panel to Base Content
                    currentPanel = pnlBaseContent;
                    // Set control in viewstate
                    this.BaseControl = filename;
                    break;
                case ControlDestination.Menu:
                    // Set current panel to Menu Content
                    currentPanel = pnlMenuContent;
                    // Set control in ViewState
                    this.MenuBaseControl = filename;
                    break;
            }

            currentPanel.Controls.Clear();
            currentPanel.Controls.Add(control);
            UpdateMenuBasePanel();
            UpdateBasePanel();

        }
        else
        {
            throw new IncorrectInheritanceException();
        }
    }
    catch (FileNotFoundException e)
    {
        HandleException(e);
    }
    catch (ArgumentNullException e)
    {
        HandleException(e);
    }
    catch (HttpException e)
    {
        HandleException(e);
    }
    catch (IncorrectInheritanceException e)
    {
        HandleException(e);
    }

}

这是 HandleException 的样子:

private void HandleException(Exception exception)
{
    // Load error control which shows big red cross
    LoadControl(ControlDestination.Menu, "~/Controls/Error.ascx", null);

    // Store error in database
    DHS.Core.DhsLogDatabase.WriteError(exception.ToString());

    // Show error in errorbox on master
    Master.ShowAjaxError(this, new CommandEventArgs("ajaxError", exception.ToString()));
}

Answer 1

你做得对(你应该只捕获你要处理的异常，并且没有办法在一个 catch block 中捕获超过一种异常类型)，但作为替代，您可以只catch(Exception ex)，检查异常类型，如果不是您期望的类型，只需再次throw，如下所示:

var exceptionTypes=new Type[] {
    typeof(FileNotFoundException),
    typeof(ArgumentNullException),
    //...add other types here
};

catch(Exception ex) {
    if(exceptionTypes.Contains(ex.GetType()) {
        HandleException(ex);
    } else {
        throw;
    }
}

更新:使用 C# 6(与 Visual Studio 2015 一起出现)，您可以改为执行以下操作:

catch(Exception ex) when (exceptionTypes.Contains(ex.GetType()) {
    HandleException(ex);
}